1. Technical Field
Various embodiments generally relate to semiconductor integrated circuits and, more particularly, to semiconductor devices and semiconductor systems including the same.
2. Related Art
Ways to reduce the weight of mobile systems such as portable computers, personal digital assistants (PDAs) and portable phones have been developed to increase the portability of these devices. Batteries that supply electric power to the mobile systems largely affect the total weight of the mobile systems. If the power consumption of the semiconductor devices employed in the mobile systems is lowered, then the capacity of the batteries may also be reduced. This in turn may then decrease the total weight of the mobile system(s). Quicker processing performance by the mobile systems are increasingly in demand with the development of multi-functional mobile systems. Accordingly, data transmission speeds of the semiconductor devices may be important factors in determination of operation speeds of the high performance mobile systems.
Semiconductor devices have been designed to simultaneously receive command signals and address signals through a plurality of pins.
In the case of synchronous semiconductor devices, the command signals and the address signals may be inputted in synchronization with a clock signal. For example, double data rate (DDR) semiconductor devices may receive command signals and address signals in synchronization with a rising edge and a falling edge of the clock signal. Whereas single data rate (SDR) semiconductor devices may receive the command signals and the address signals in synchronization with a rising edge of the clock signal.